Valve-chest construction for steam engines



May 5, 1925. 1,535,798.

w. J. KNOX VALVE CHEST CONS'RRUCTION FOR STEAM ENGiNES Filed Feb. 9. 1924 3 ShetsShet 1 ray. *1.

13 INVENTOR.

A TTORNEYS.

May 5, 1925. 15361798 I w. J. KNOX VALVE CHEST CONSTRUCTION FOR STEAM ENGINES Filed Feb. 1924 3 Sheets-Sheet 2 JJ EL 11 1 i 25 l 7 n 25 l L h L-J L J j J J NVENTOR.

. A TTORNEYS.

May 5; 1925. 1,536,798 W. J. KNOX 'VALVE CHEST CONSTRUCTION FOR STEAM ENGINES Filed Feb. 9 1924 3 SheetsE-Sheet 5 IN VEN TOR.

ATTORNEYS.

Patented May I 5, 7 1925.

- "WI-Lillian J. Knox, or UBoIs, PEINN$YLVA1\TIA. 7

AL E-casein eonscsscmoiw FOR ST AM nNGrNEs.

1 Applicetion med Fehruary 9, 1924. serial No. 691,575.

To all whom it may concern:

Be it known that I, VVILnrAM J. "Knox, a

citizen of the United States, ands resident of Dubois, in the county "of clezn' field and State of Pennsylvania, have made a newmid,

useful invention, in Improvements in a Valve Chest "Construction for lsteaim Engins-55,015 which the fol-lowing is specifica tion. 7

lh'einvention relates t o valve chest constructions for steam engines, and'particularly locomotive engines, Which it is desired tosuhstitute piston valves for the slide valves in order :to adapt um engines to the i use of superheated steam at high temper nture, it being recognized as impracticwhle to use superheated steam with slide valves "because o-fthe difficulty of lubricating such valves. Various rcxpedients. for ana kingsuch substitution have "been attempted, calling" for special steam chests-and valve cl'ianibers bolted "to the cylinders and employ-111g ,g'as

lzets to insure tight joints 'between the parts,

but in practicepit has been found very diilicult to make the joints tight and maintain them in such condition ilr'service. It is the object of the present invention to overcome this -difiiculty iand. PI'OV-IClG a, YCOHSCPUCUOII which CEIIlrlJG applied withoutrdi-fliculty, and

In the construction, as hereinafter de scribed, and illustrated in the drawings, the

steam chest is .held in place 4011 the cylinder in the usual Way "by studs with nuts and by belts, with :agasket/01" securing ii-tight joint. Inside this chest is avalve easinggor cl'ian'ililer member, in thehl'orm lot a casting carrying afipistonvidve. This casing" is secured "in place on thecy'linder :hy the air-.1

togenous Welding process,-ra 1 1d, when welded in :15] see, becomes in effect integral with the cylinder, .so that there "is no possibility of leakage. As locomotive cylinders-ere pra'c ticallyallcast of grey iron, which does not readily yield :to the welding process, a false valve seat ol'iopen hearth steel, or Wrought iron, which is readilyweldable, is fittedto the face o'tf the cylinder surrounding the ports,

and secured rigidly'in place.- The valve carsing or chamber ineinber isaa steel casting, which is readily Weldahle to the false seat.

If the "cylinder proper should itself be n steel casting, or eat a material which is readily welda'ble, the false valve seatmay be dispensed with. On'e 'enlbodinient of the invention is illustrated drawings, wherein:

Figure l is a .longituc'l'inzvl section through the cylinder face, the. stea in "chest, valve chamber, valve chamber bushing, valve and associated parts. Fig. 2 is h plan scctiono'f the chest andisvalve ohan'iloer tirhen on the line I-III I of Fig. 1. is a halllf in the accompanying cross section ontho line III-PIII of Fig. 1,

and a half elevation of theright hand end of the chest.-

4 as agplan section berrbeing shown in :place, while v in'the other nan it is omitted to better, show the ports and fa lseva lve seat. Fig. =5 is a 'half plan said il ia'lai, "section of the valve cl'iani'ber on the line V'V oft Fig; 7. 6 rise vertical section ofthe Vil lVB-CllUl-l: ber taken *onrthe line Vi -VI of Fig. 7. Fig. 7 is a halt cross section 'fillld half end view through the chest-foils half the valve cha-ur of the valve chamber. ,ATlCl' Figs. 8 and '9 are plan and ele ation viewsrespectively of the cover strip.

'lReferr-nig to th'edrawings, -1 is theengiue cyl inder heuin the steam (ports 2 and 3 and the exhaust .port 4 of the usual construction.

,Mounted on the u oer side of the cylinder Wall and surrounding the ends of the ports is the false valve-seat 5 which .is secured in place "by. means of the boltsG, such seat being "of a readily Weldable inetal such as wrought iron or open hearth steel.

or chamber l7, such-casing being of cestf steel 'or other Inetal,which'can be elded. This casini'gis secured to the-seat 5"by welding it (st-"theedges-inside, and-out, along the lines 8, 10, 11, 12 and 13. The inside welding along the lines9 and 10 is accomplished through the opening 14 1 and 7 in the top of the casi1rg,'before the segmental cover stripl5 is applied, such strip being secured in position by Weldingalong the lines 16. y

The casing is also provided with the cross Walls 17, 18, 19 and 20 (Fig. 2-), and tln'oirig-h these Walls circular holes are bored in true a-lignn ient. and in these is pressed or shrunk the valve bushing 21. The valve 22 shown is of the double ipiston head and spool type, but any suitable piston valve may beoniployed, and motion is imparted to it through the stem 23 connectedto the usual valve niotion. I r Fitting over the Valve casing 7 is the steam chest 24:, such chest being secured in place by the stud bolts 25 screwed into the cylinder wall at their lower ends and provided with the nuts 26. Additional securing means at the rear end of the chest is provided by the bolts 27, which extend through the bottom wall of the steam chest (Figs. 1 and 2) and into the top cylinder wall. The rear end of the steam chest is provided with a D shaped opening 28, to permit the insertion and removal of the valve without disengaging the chest from the cylinder. This opening is closed by the cover plate 29 secured by the bolts 30. This opening also permits of the introduction of the two bolts 27. Suitable gaskets to prevent leakage are provided beneath the heads of these bolts and also between the lower edges of the chest and the upper face of the cylinder upon which the chest is supported.

It will be seen that the improved structure achieves the objects heretofore .set forth. The casing or chamber 7 is attached very securely to the false seat by the welding operation, and the lines of. welding, in addition to securing the chamber securely in place, prevents the passage of steam from port to port and also the passage from the chest to the middle section of the valve. The welding on the inside lines 9 and 10 is made possible by the use of the are shaped opening 14: which is subsequently permanently closed by the cover strip 15. The structure is readily applicable to practically all engines heretofore equipped with slide valves at a relatively low cost and with a resulting structure of a most substantial character which requires a minimum of attention in maintenance, and in which any leakage at the joints is reduced to a minimum. The false seat 5 can be secured so that there is no leakage between its lower surface and the top surface of the cylinder surrounding the parts, since the bolts or screws 6 can be placed closely enough to secure this result, and can also be placed through the strips lying between the central port i and the ports 2 and 3, so that there is no leakage beneath these strips. It the false seat were dispensed with, it would be practically impossible to secure the casing down upon the top surface of the cylinder by screws or bolts in such manner as to prevent leakage, because of the ditliculty of locating the screws or bolts around the periphery of the casing in such manner as to make a permanently tight joint, and because screws could not be inserted through the strip portions lying between the port 4 and the ports 2 and \Vithout tight joints at these latter points, leakage would occur between the ports.

What I claim is:

1. The combination with a cast cylinder of metal not readily subject to a welding operation and having ports through one side, of a seat, comprising a sheet of wcldable material secured to the cylinder by screw means and surrounding the ports, a valve casing mounted on such seat and welded thereto along its periphery and also interiorly along lines lying between the ports, a piston valve mounted in the casing, and a steam chest surrounding the valve casing secured to the cylinder.

2. T he combination with a cast iron cylinder having ports through one side and a seat, comprising a sheet of weldable metal surrounding the ports secured by screw means to such cylinder with a steam-tight joint, a valve casing mounted on such seat and welded thereto around its periphery and also along lines between the ports, a piston valve mounted in the casing, and a steam chest surrounding the valve casing and secured to the cylinder.

3. The combination with a cast cylinder of metal not readily subject to a welding operation and having ports through one side, of a seat, comprising a sheet of weldable material secured to the cylinder by screw means and having a steam-tight contact therewith, a valve casing mounted on such seat and welded thereto along both its inner edges and its outside edges, and having an opening through its upper side for giving access to the interior for the welding operation along said inside edges, :1 cover plate for said opening, a piston valve mounted in the casing, and a steam chestsurrounding the casing and secured to the cylinder.

4%. The combination with a cast cylinder of metal not readily subject to a welding operation and having ports through one side, of a seat comprising a sheetof weldable material secured to the cylinder by means of a series of screws and surrounding the ports, a valve casing mounted on such seat and welded thereto along both its inside edges and its outside edges and having an opening through its upper side for giv ing access to the interior for the welding operation, a cover plate for said opening welded to the casing, a piston valve mounted in the casing and a steam chest surrounding the casing and secured to the cylinder. d

5. The combination with a cast cylinder of metal not readily subject to a welding operation and having ports through one side, of a seat of weldable material secured to the cylinder by a series of screws having a steam-tight contact therewith and surrounding the ports, a valve casing mounted on such seat and welded thereto and provided with ports, and having an opening through its upper side for giving access to the interior for the welding operation. a cover plate for said opening, a piston valve mounted in the casing, a steam chest surmemes rounding the casing and secured to the cyL inder, a removable cover plate for'one endthrough rtheloWer Wall of the steam chestinto the cylinder Wall and having their heads accessible through the end of'the steam chest when the cover plate is removed- 6. The combination With a cylinder having ports through one side and aseat surrounding the ports, of a valve casing mounted on such seat and secured thereto and provided with ports, a piston Valve in the casing, a steam chest surrounding the casing and bolted thereto with an opening at one end opposite theend of the piston, a

removable cover plate for said opening, and

securing stud bolts extending through the lower Wall of the'steam chest into the cyl indei' all and having their heads accessible through the end of the steam chest when the cover plate is removed.

In testimony where0f,j I have hereunto subscribed my name this (3th day of February, 1924-.

WILLIAM J. KNOX. 

